76291-90-2Relevant academic research and scientific papers
Enantioselective protecting-group-free synthesis of (+)-9,10-dihydroecklonialactone B
Yassen, Asmaa Said Ali,Ishihara, Jun,Hatakeyama, Susumi
, p. 59 - 63 (2017/02/26)
An enantioselective protecting-group-free route to ecklonialactones, C-18 oxylipins isolated from the brown algae, was demonstrated by the synthesis of (+)-dihydroecklonialactone B from (E)-ethyl hex-3-enoate in 17 steps.
Synthetic approach toward cis-disubstituted γ- And δ-lactones through enantioselective dialkylzinc addition to aldehydes: Application to the synthesis of optically active flavors and fragrances
Pisani, Laura,Superchi, Stefano,D'Elia, Alessandra,Scafato, Patrizia,Rosini, Carlo
experimental part, p. 5779 - 5784 (2012/09/08)
A versatile and straightforward approach to optically active cis-4,5-disubstituted γ- and δ-lactones by catalytic enantioselective addition of dialkyzincs to cinnamic aldehydes and RCM ring closure has been reported. The synthetic importance of the enantioselective dialkylzinc alkylation of aldehydes has been thus widened. Such an approach has then been employed for the enantioselective synthesis of naturally occurring γ-lactone flavors like (S)-5-ethyl-butanolide (6a) and (4S,5S)-cis-whisky lactone (6b) and extended to the preparation of δ-lactones like (5S,6S)-5-methyl-6-ethylpentanolide (9a), precursor of the pheromone serricornin.
Copper catalyzed asymmetric synthesis of chiral allylic esters
Geurts, Koen,Fletcher, Stephen P.,Feringa, Ben L.
, p. 15572 - 15573 (2007/10/03)
The complex derived from Taniaphos ligand 4 and CuBr?Me2S catalyzes the asymmetric addition of Grignard reagents to 3-bromopropenyl esters 1 to provide allylic esters 2 in high yields and high chemio-, regio-, and enantioselectivities. The work demonstrates that allylic asymmetric alkylation (AAA) can be done on substrates bearing a heteroatom at the γ-position. The method is a practical route to chiral, nonracemic allylic alcohols. The use of functionalized substrates 1 or Grignard reagents leads to more complex products 2, which can be further manipulated as demonstrated in conversion to (S)-5-ethyl-2(5H)-furanone 6 and (S)-benzoic acid-cyclopent-2-enyl ester 7. Copyright
Synthetic studies on himbacine, a potent antagonist of the muscarinic M2 subtype receptor. Part 2: Synthesis and muscarinic M2 subtype antagonistic activity of the novel himbacine congeners modified at the C-3 position of lactone moiety
Takadoi, Masanori,Yamaguchi, Kentaro,Terashima, Shiro
, p. 1169 - 1186 (2007/10/03)
With an aim to disclose the convergency and flexibility of our previously explored synthetic route to natural himbacine 1, and moreover, to clarify some novel aspects of the structure-activity relationships of 1, we prepared various structural types of novel himbacine congeners, 3-demethylhimbacine (3-norhimbacine) 2 and 4-epi-3-demethylhimbacine (4-epi-3-norhimbacine) 4-epi-2 and their enantiomers (ent-2 and ent-4-epi-2), 11-methylhimbacine 3, and 3-epihimbacine 4 in optically pure forms by employing our methodology. All of the synthesized congeners correspond to the compounds modified at the C-3 position of γ-lactone moiety involved in 1. Among these congeners, 3-demethylhimbacine (3-norhimbacine) 2 was found to exhibit more potent muscarinic M2 receptor binding affinity than natural 1.
Kinetic resolution of racemic lactones by conjugate additions of allylic organolithium species: Direct formation of three contiguous centers with high diastereo- and enantioselectivities
Lim, Sung H.,Beak, Peter
, p. 2657 - 2660 (2007/10/03)
(Matrix presented) Kinetic resolution of racemic α,β-unsaturated lactones by the organolithium species produced from asymmetric lithiation of N-Boc-N-(p-methoxyphenyl)cinnamylamine provides conjugate addition products with three contiguous stereogenic centers in yields of 62-77% with diastereomeric ratios from 75:25 to >99:1 and enantiomeric ratios for the major diastereomers from 94:6 to 98:2.
A sulfur-containing diselenide as an efficient chiral reagent in asymmetric selenocyclization reactions
Tiecco, Marcello,Testaferri, Lorenzo,Marini, Francesca,Sternativo, Silvia,Bagnoli, Luana,Santi, Claudio,Temperini, Andrea
, p. 1493 - 1502 (2007/10/03)
Treatment of the di-2-[(1S)-1-(methylthio)ethyl]phenyl diselenide with bromine and silver triflate afforded the corresponding selenyl triflate which was used in situ as a strongly electrophilic selenium reagent to effect the asymmetric synthesis of oxygen- or nitrogen-containing heterocycles. Cyclic ethers, lactones, lactams or N-protected pyrrolidines have been prepared in good yield with complete regioselectivity and high diastereoselectivity.
Highly Enantioselective Synthesis of Both Enantiomers of γ-Substituted Butenolides by Bakers' Yeast Reduction and Lipase-Catalyzed Hydrolysis. Total Synthesis of (3AS,6aS)-Ethisolide, Whisky Lactone, and (-)-Avenaciolide
Tsuboi, Sadao,Sakamoto, Jun-Ichi,Yamashita, Hiroshi,Sakai, Takashi,Utaka, Masanori
, p. 1102 - 1108 (2007/10/03)
Reduction of 3-chloro-4-oxoalkanoates 5 with bakers' yeast gave (4S)-3-chloro-4-hydroxyalkanoates, which were hydrolyzed and dehydrochlorinated to give (γS)-alkylbutenolides with >96% ee. Reduction of 5 with NaBH4 gave syn-3-chloro-4-hydroxyalkanoate 6. Asymmetric hydrolysis of syn-4-chloro-3-hydroxyalkanoate (±)-10 with lipase afforded (3R,4R)-6 and (3S,4S)-10 with high optical purities. Hydrolysis and dehydrochlorination of (3R,4R)-6 gave (γA)-alkylbutenolides with >85% ee. Total syntheses of (3aS,6aS)-ethisolide, whisky lactone, and (-)-avenaciolide from these butenolides are described.
Pure Enantiomers from Retro-Diels-Alder Processes
Beckmann, Marion,Hildebrandt, Hinrich,Winterfeldt, Ekkehard
, p. 335 - 345 (2007/10/02)
Diastereoselective and regioselective transformations of cycloadducts to enantiomerically pure cyclopentadienes are reported.Retro-Diels-Alder processes finally give rise to pure enantiomers in high yield.
CHEMISTRY OF BAKER'S YEAST REDUCTION PRODUCTS: USE OF OPTICALLY ACTIVE (S)-(+)-1-(p-TOLUENESULFONYL)PROPAN-2-OL AND (S)-(+)-1-(PHENYLSULFONYL)PROPAN-2-OL IN SYNTHESIS.
Kozikowski, Alan P.,Mugrage, B.B.,Li, C.S.,Felder, L.
, p. 4817 - 4820 (2007/10/02)
The utility of the title compounds in the preparation of optically active lactones and alcohols is detailed.
